SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24dc8736237e71ee67bbedb339dbb27ca241514ce8510af1581b7971c1364ecd' 
  AND token = '5KrlqjVKya+4gJy3Pl/Sag14j5QynuQQOhqYfB7FvVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}